I work with two fix systems: one win32 with Perl in C:/Perl/bin/perl and several identically built linuxes with Perl in /usr/bin/perl and if I have to migrate serveral scripts from on system to the other, I open all scripts in Phase 5, my favourite html-editor on win32 and do a search and replace on the shebang over all opened files.
Alternatively you could always write a short search and replace script, that changes the shebang-line accordingly.

 
neophyte